Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 77
Filtrar
1.
Immunohematology ; 39(2): 72-76, 2023 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-37405848

RESUMO

This update of the Landsteiner-Wiener (LW) blood group system (Grandstaff Moulds MK. The LW blood group system: a review. Immunohematology 2011;27:136-42. Storry JR. Review: the LW blood group system. Immunohematology 1992;8:87-93) reports new information on the distribution of genetic variants in ICAM4 and reviews the complex serologic identification of the high-prevalence LWEM antigen. The role of ICAM4 in sickle cell disease and malaria susceptibility is discussed.


Assuntos
Anemia Falciforme , Antígenos de Grupos Sanguíneos , Humanos , Anemia Falciforme/genética , Antígenos de Grupos Sanguíneos/genética
2.
Vox Sang ; 112(3): 279-287, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-28220510

RESUMO

BACKGROUND AND OBJECTIVES: Variant RHD genes associated with the weak D phenotype can result in complete or partial D-epitope expression on the red cell. This study examines the genetic classification in Australian blood donors with a weak D phenotype and correlates RHD variants associated with the weak D phenotype against D-epitope profile. MATERIALS AND METHODS: Following automated and manual serology, blood samples from donors reported as 'weak D' (n = 100) were RHD genotyped by a commercial SNP-typing platform and Sanger sequencing. Two commercial anti-D antibody kits were used for extended serological testing for D-epitope profiles. RESULTS: Three samples had wild-type RHD exonic sequences, and 97 samples had RHD variants. RHD*weak D type 1, RHD*weak D type 2 or RHD*weak D type 3 was detected in 75 donors. The remaining 22 samples exhibited 17 different RHD variants. One donor exhibited a novel RHD*c.939+3A>C lacking one D-epitope. Weak D types 1·1, 5, 15, 17 and 90 showed a partial D-epitope profile. CONCLUSION: The array of RHD variants detected in this study indicated diversity in the Australian donor population that needs to be accommodated for in future genotyping strategies.


Assuntos
Doadores de Sangue/estatística & dados numéricos , Sistema do Grupo Sanguíneo Rh-Hr/genética , Alelos , Austrália , Sequência de Bases , Transfusão de Sangue , DNA/química , DNA/isolamento & purificação , DNA/metabolismo , Epitopos/imunologia , Epitopos/metabolismo , Éxons , Frequência do Gene , Genótipo , Humanos , Isoanticorpos/sangue , Fenótipo , Polimorfismo de Nucleotídeo Único , Imunoglobulina rho(D)/sangue , Análise de Sequência de DNA , Testes Sorológicos
3.
Eur J Cancer Care (Engl) ; 25(5): 795-805, 2016 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-27283004

RESUMO

In this study, we assessed the quality of publicly available cancer-related physical activity (PA) information appearing on reputable sites from Canada and other English-speaking countries. A cross-sectional Internet search was conducted on select countries (Canada, USA, Australia, New Zealand, UK) using Google to generate top 50 results per country for the keywords "'physical activity' AND 'cancer'". Top results were assessed for quality of PA information based on a coding frame. Additional searches were performed for Canadian-based sites to produce an exhaustive list. Results found that many sites offered cancer-related PA information (94.5%), but rarely defined PA (25.2%). Top 50 results from each country did not differ on any indicator examined. The exhaustive list of Canadian sites found that many sites gave information about PA for survivorship (78.3%) and prevention (70.0%), but rarely defined (6.7%) or referenced PA guidelines (28.3%). Cancer-related PA information is plentiful on the Internet but the quality needs improvement. Sites should do more than mention PA; they should provide definitions, examples and guidelines. With improvements, these websites would enable healthcare providers to effectively educate their patients about PA, and serve as a valuable resource to the general public who may be seeking cancer-related PA information.


Assuntos
Exercício Físico , Internet/normas , Neoplasias , Educação de Pacientes como Assunto/normas , Análise de Variância , Austrália , Canadá , Estudos Transversais , Sistemas de Informação em Saúde/normas , Sistemas de Informação em Saúde/estatística & dados numéricos , Sistemas de Informação em Saúde/provisão & distribuição , Humanos , Internet/estatística & dados numéricos , Internet/provisão & distribuição , Nova Zelândia , Educação de Pacientes como Assunto/estatística & dados numéricos , Qualidade da Assistência à Saúde , Reino Unido , Estados Unidos
4.
Front Sports Act Living ; 6: 1332376, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38774277

RESUMO

Introduction: Moderate-to-high physical activity participation is associated with a reduced risk of infertility. Yet, exercise interventions that target cardiorespiratory fitness, independent of weight loss, are lacking in obesity and female fertility research. Purpose: The primary objective of the PRO-FIT-CARE (PROmoting FITness for CArdiometabolic & REproductive Health) study was to assess the feasibility of a moderate-to-high-intensity online exercise program for persons with obesity and female infertility. Methods: Feasibility, safety, acceptability, and efficacy were assessed by examining: (1) recruitment and consent rate, (2) study retention, (3) adverse events, (4) participant satisfaction, (5) adherence, and (6) cardiorespiratory fitness. Results: Eleven of thirty-two women contacted agreed to participate in the program (34.4% consent rate). Eight participants (72.7%) completed the study. One musculoskeletal injury was reported. There was a 30% adherence rate based on prescribed exercise intensity (60%-80% of heart rate maximum). One of eleven participants attended 80% of the exercise intervention. Based on a weekly satisfaction survey, the program had an overall high level of satisfaction. Compared to sex and age normative data, post-intervention, two of eight participants improved their cardiorespiratory fitness percentile rank. Conclusion: The study highlights challenges with adherence to an online exercise program. While the program was safe and participants reported high levels of program satisfaction, approaches to improve adherence must be incorporated.

5.
Nat Genet ; 25(4): 402-5, 2000 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-10932182

RESUMO

Neurofibrillary tangles (NFT) composed of the microtubule-associated protein tau are prominent in Alzheimer disease (AD), Pick disease, progressive supranuclear palsy (PSP) and corticobasal degeneration (CBD). Mutations in the gene (Mtapt) encoding tau protein cause frontotemporal dementia and parkinsonism linked to chromosome 17 (FTDP-17), thereby proving that tau dysfunction can directly result in neurodegeneration. Expression of human tau containing the most common FTDP-17 mutation (P301L) results in motor and behavioural deficits in transgenic mice, with age- and gene-dose-dependent development of NFT. This phenotype occurred as early as 6.5 months in hemizygous and 4.5 months in homozygous animals. NFT and Pick-body-like neuronal lesions occurred in the amygdala, septal nuclei, pre-optic nuclei, hypothalamus, midbrain, pons, medulla, deep cerebellar nuclei and spinal cord, with tau-immunoreactive pre-tangles in the cortex, hippocampus and basal ganglia. Areas with the most NFT had reactive gliosis. Spinal cord had axonal spheroids, anterior horn cell loss and axonal degeneration in anterior spinal roots. We also saw peripheral neuropathy and skeletal muscle with neurogenic atrophy. Brain and spinal cord contained insoluble tau that co-migrated with insoluble tau from AD and FTDP-17 brains. The phenotype of mice expressing P301L mutant tau mimics features of human tauopathies and provides a model for investigating the pathogenesis of diseases with NFT.


Assuntos
Neurite do Plexo Braquial/genética , Transtornos dos Movimentos/genética , Emaranhados Neurofibrilares/genética , Proteínas tau/genética , Substituição de Aminoácidos , Animais , Tronco Encefálico/metabolismo , Tronco Encefálico/patologia , Tronco Encefálico/ultraestrutura , Contagem de Células , Expressão Gênica , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos DBA , Camundongos Transgênicos , Músculo Esquelético/metabolismo , Músculo Esquelético/patologia , Músculo Esquelético/ultraestrutura , Mutação , Neurônios/patologia , Neurônios/ultraestrutura , Medula Espinal/metabolismo , Medula Espinal/patologia , Medula Espinal/ultraestrutura
6.
Animal ; 17(5): 100792, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-37121156

RESUMO

Random regression modelling has been used across multiple animal species to model longitudinal data. The random regression model for growth accounts for the genetic correlation between measures of the same trait over time and the wide environmental variability in growth, but this requires adequate weight records across the age range. However, contemporary management practices in sheep in the United Kingdom generally focus on growing lambs and neglect mature weight recordings. This study examined modelling strategies for growth data in Suffolk and Charollais sheep, provided by the Agriculture and Horticulture Development Board, with polynomial random regression modelling with many early life weight recordings but limited weight recordings in mature animals. Two methods were employed to model the data. In Method A, missing mature weight records were predicted for those animals that did not have a recorded mature weight. The animals were sorted into groups based on the identity of their sires and the year in which the animal was born. Mature weight values were predicted within each group with a multiple regression model. The dataset, including predicted values, was analysed with random regression models using polynomials and simple linear regression for animal and permanent environmental (PE) effects. In Method B, the dataset with missing mature weight records was analysed using a random linear regression animal model with random animal and PE effects. Due to problems of convergence because the parameters were close to the boundary space, fixing the correlation between the intercept and slope of the Legendre polynomial at different levels was investigated. The heritability values resulting from the model with a fixed correlation between intercept and slope parameters at 0.5 for the Suffolk dataset resulted in heritability values ranging from 0.2 to 0.5 from 1 to 619 days of age. Corresponding estimates for the Charollais dataset ranged from 0.18 to 0.49 from 1 to 640 days of age. For the Suffolk data, the genetic correlations ranged from 1.00 to 0.08 between weight at day 1 to weight at day 619, while for the Charollais, the correlations ranged from 1.00 to 0.05 from 1 to 640 days of age. Validation procedures were undertaken using a multitrait approach to examine the estimated breeding values when the correlation between the intercept and slope are fixed at different levels. The results indicated that fixing the correlation at 0.5 gave the most appropriate estimates for the Suffolk and Charollais datasets.


Assuntos
Clima , Carneiro Doméstico , Ovinos/genética , Animais , Carneiro Doméstico/genética , Peso Corporal/genética , Fenótipo , Modelos Lineares , Modelos Genéticos
7.
Nat Med ; 4(1): 97-100, 1998 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-9427614

RESUMO

Genetic causes of Alzheimer's disease (AD) include mutations in the amyloid precursor protein (APP), presenilin 1 (PS1), and presenilin 2 (PS2) genes. The mutant APP(K670N,M671L) transgenic line, Tg2576, shows markedly elevated amyloid beta-protein (A beta) levels at an early age and, by 9-12 months, develops extracellular AD-type A beta deposits in the cortex and hippocampus. Mutant PS1 transgenic mice do not show abnormal pathology, but do display subtly elevated levels of the highly amyloidogenic 42- or 43-amino acid peptide A beta42(43). Here we demonstrate that the doubly transgenic progeny from a cross between line Tg2576 and a mutant PS1M146L transgenic line develop large numbers of fibrillar A beta deposits in cerebral cortex and hippocampus far earlier than their singly transgenic Tg2576 littermates. In the period preceding overt A beta deposition, the doubly transgenic mice show a selective 41% increase in A beta42(43) in their brains. Thus, the development of AD-like pathology is substantially enhanced when a PS1 mutation, which causes a modest increase in A beta42(43), is introduced into Tg2576-derived mice. Remarkably, both doubly and singly transgenic mice showed reduced spontaneous alternation performance in a "Y" maze before substantial A beta deposition was apparent. This suggests that some aspects of the behavioral phenotype in these mice may be related to an event that precedes plaque formation.


Assuntos
Doença de Alzheimer/genética , Doença de Alzheimer/fisiopatologia , Precursor de Proteína beta-Amiloide/genética , Proteínas de Membrana/genética , Doença de Alzheimer/patologia , Precursor de Proteína beta-Amiloide/biossíntese , Análise de Variância , Animais , Encéfalo/patologia , Córtex Cerebral/patologia , Cruzamentos Genéticos , Genótipo , Proteína Glial Fibrilar Ácida/análise , Humanos , Proteínas de Membrana/biossíntese , Camundongos , Camundongos Transgênicos , Atividade Motora , Postura , Presenilina-1 , Desempenho Psicomotor , Reflexo , Convulsões
8.
Science ; 200(4337): 50-1, 1978 Apr 07.
Artigo em Inglês | MEDLINE | ID: mdl-635570

RESUMO

The protease inhibitors leupeptin and pepstatin were used in vivo in genetically dystrophic chickens to determine their effects on the histological and biochemical changes observed in this disease. These compounds appear to delay the degeneration of muscle tissue which is characteristic of this disorder and thus may have potential therapeutic value in the treatment of muscular dystrophy.


Assuntos
Leupeptinas/uso terapêutico , Distrofia Muscular Animal/tratamento farmacológico , Oligopeptídeos/uso terapêutico , Pepstatinas/uso terapêutico , Animais , Galinhas , Creatina Quinase/sangue , Músculos/patologia , Distrofia Muscular Animal/enzimologia , Distrofia Muscular Animal/patologia
9.
Science ; 240(4852): 643-6, 1988 Apr 29.
Artigo em Inglês | MEDLINE | ID: mdl-2896386

RESUMO

Screening for human T-lymphotropic virus type I (HTLV-I) antibodies was performed on sera from 39,898 blood donors at eight blood centers in geographically distinct areas of the United States. Ten donors (0.025 percent) showed evidence of HTLV-I seropositivity by enzyme immunoassays; this was confirmed by protein immunoblot and radioimmunoprecipitation. Seroprevalence rates ranged from 0 to 0.10 percent at the locations sampled, with HTLV-I antibodies found predominantly in donors from the southeastern and southwestern United States. Matched case-control interviews and laboratory studies were performed on five seropositive women and two seropositive men who participated in an identity-linked collection of sera from a subset of 33,893 donors at six of the eight blood centers. Four of the women and both men are black; one woman is Caucasian. Four of the seven seropositive individuals admitted to prior intravenous drug abuse or sexual contact with an intravenous drug user. Sexual contact with native inhabitants of an HTLV-I endemic area was the only identified risk factor for one male. The distribution of HTLV-I antibodies in this U.S. blood donor sample corroborates the previously reported epidemiology of this agent and suggests that additional donor screening measures, including the testing of donated blood for HTLV-I markers, may be necessary to prevent the spread of HTLV-I to transfusion recipients.


Assuntos
Anticorpos Antivirais/análise , Doadores de Sangue , Infecções por Deltaretrovirus/epidemiologia , Deltaretrovirus/imunologia , Adulto , Deltaretrovirus/isolamento & purificação , Infecções por Deltaretrovirus/diagnóstico , Infecções por Deltaretrovirus/transmissão , Feminino , Humanos , Técnicas Imunoenzimáticas , Técnicas de Imunoadsorção , Japão , Masculino , Pessoa de Meia-Idade , Fatores de Risco , Parceiros Sexuais , Transtornos Relacionados ao Uso de Substâncias , Estados Unidos
10.
Science ; 293(5534): 1487-91, 2001 Aug 24.
Artigo em Inglês | MEDLINE | ID: mdl-11520987

RESUMO

JNPL3 transgenic mice expressing a mutant tau protein, which develop neurofibrillary tangles and progressive motor disturbance, were crossed with Tg2576 transgenic mice expressing mutant beta-amyloid precursor protein (APP), thus modulating the APP-Abeta (beta-amyloid peptide) environment. The resulting double mutant (tau/APP) progeny and the Tg2576 parental strain developed Abeta deposits at the same age; however, relative to JNPL3 mice, the double mutants exhibited neurofibrillary tangle pathology that was substantially enhanced in the limbic system and olfactory cortex. These results indicate that either APP or Abeta influences the formation of neurofibrillary tangles. The interaction between Abeta and tau pathologies in these mice supports the hypothesis that a similar interaction occurs in Alzheimer's disease.


Assuntos
Doença de Alzheimer/patologia , Peptídeos beta-Amiloides/metabolismo , Precursor de Proteína beta-Amiloide/metabolismo , Encéfalo/patologia , Emaranhados Neurofibrilares/patologia , Placa Amiloide/patologia , Proteínas tau/metabolismo , Doença de Alzheimer/genética , Doença de Alzheimer/metabolismo , Precursor de Proteína beta-Amiloide/genética , Animais , Encéfalo/metabolismo , Cruzamentos Genéticos , Modelos Animais de Doenças , Feminino , Sistema Límbico/metabolismo , Sistema Límbico/patologia , Masculino , Camundongos , Camundongos Transgênicos , Mutação , Degeneração Neural , Emaranhados Neurofibrilares/genética , Emaranhados Neurofibrilares/metabolismo , Neurônios/ultraestrutura , Fragmentos de Peptídeos/metabolismo , Placa Amiloide/genética , Placa Amiloide/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Caracteres Sexuais , Solubilidade , Medula Espinal/metabolismo , Medula Espinal/patologia , Proteínas tau/genética
11.
Physiother Theory Pract ; 35(11): 1044-1060, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-29733739

RESUMO

Background: Investigation of the leadership capabilities of physiotherapy managers found that they report predominantly demonstrating capabilities associated with the human resource and structural frames. However, little is known about the leadership capabilities of clinical specialists and advanced physiotherapy practitioners (APPs) who also are identified as having responsibility for leadership. Objective: To explore clinical specialists´ and APPs' perceptions of their leadership capabilities and compare them with the reported leadership capabilities of physiotherapy managers. Methods: Semi-structured interviews were conducted with a purposive sample of 17 physiotherapy clinical specialists and APPs from a range of practice settings across Ireland. The interviews were analyzed using template analysis and the coding template was based on the Bolman and Deal Leadership framework. Results: The participants described demonstrating leadership capabilities associated with each of the four leadership frames. However, the language used by the clinical specialists/APPs suggested that they work predominantly through the human resource frame. Structural frame capabilities were reported by the clinical specialists/APPs and there were some differences to those reported by the managers. In keeping with the reported leadership capabilities of the physiotherapy managers, the employment of capabilities associated with the political frame varied between participants and symbolic frame capabilities were underused. Conclusion: There are many similarities in the self-reported leadership capabilities of managers and clinical specialists/APPs. However, differences were also noted. Both cohorts of physiotherapy leaders may benefit from specific development programs to develop leadership capabilities associated with the political and symbolic frames.


Assuntos
Atitude do Pessoal de Saúde , Liderança , Fisioterapeutas , Especialização , Feminino , Humanos , Irlanda , Masculino , Pesquisa Qualitativa
12.
J Perinatol ; 38(2): 185-190, 2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-28906495

RESUMO

OBJECTIVE: To evaluate effects of a transition home program (THP) and risk factors on emergency room (ER) use within 90 days of discharge for preterm (PT) infants <37 weeks gestation. STUDY DESIGN: This is a prospective 3-year cohort study of 804 mothers and 954 PT infants. Mothers received enhanced neonatal intensive care unit transition support services until 90 days postdischarge. Regression models were run to identify the effects of THP implementation year and risk factors on ER visits. RESULTS: Of the 954 infants, 181 (19%) had ER visits and 83/181 (46%) had an admission. In regression analysis, THP year 3 vs year 1 and human milk at discharge were associated with decreased risk of ER visits, whereas increased odds was associated with non-English speaking, maternal mental health disorders and bronchopulmonary dysplasia. CONCLUSION: Enhanced THP services were associated with a 33% decreased risk of all ER visits by year 3. Social and environmental risk factors contribute to preventable ER visits.


Assuntos
Serviço Hospitalar de Emergência/estatística & dados numéricos , Serviços de Assistência Domiciliar/estatística & dados numéricos , Recém-Nascido Prematuro , Cuidado Transicional , Feminino , Idade Gestacional , Serviços de Assistência Domiciliar/economia , Humanos , Lactente , Recém-Nascido , Cobertura do Seguro , Modelos Logísticos , Masculino , Alta do Paciente , Estudos Prospectivos , Rhode Island , Medição de Risco , Fatores de Risco , Fatores de Tempo
13.
mBio ; 7(4)2016 07 19.
Artigo em Inglês | MEDLINE | ID: mdl-27435464

RESUMO

UNLABELLED: Zika virus (ZIKV) is a mosquito-borne flavivirus responsible for thousands of cases of severe fetal malformations and neurological disease since its introduction to Brazil in 2013. Antibodies to flaviviruses can be protective, resulting in lifelong immunity to reinfection by homologous virus. However, cross-reactive antibodies can complicate flavivirus diagnostics and promote more severe disease, as noted after serial dengue virus (DENV) infections. The endemic circulation of DENV in South America and elsewhere raises concerns that preexisting flavivirus immunity may modulate ZIKV disease and transmission potential. Here, we report on the ability of human monoclonal antibodies and immune sera derived from dengue patients to neutralize contemporary epidemic ZIKV strains. We demonstrate that a class of human monoclonal antibodies isolated from DENV patients neutralizes ZIKV in cell culture and is protective in a lethal murine model. We also tested a large panel of convalescent-phase immune sera from humans exposed to primary and repeat DENV infection. Although ZIKV is most closely related to DENV compared to other human-pathogenic flaviviruses, most DENV immune sera (73%) failed to neutralize ZIKV, while others had low (50% effective concentration [EC50], <1:100 serum dilution; 18%) or moderate to high (EC50, >1:100 serum dilution; 9%) levels of cross-neutralizing antibodies. Our results establish that ZIKV and DENV share epitopes that are targeted by neutralizing, protective human antibodies. The availability of potently neutralizing human monoclonal antibodies provides an immunotherapeutic approach to control life-threatening ZIKV infection and also points to the possibility of repurposing DENV vaccines to induce cross-protective immunity to ZIKV. IMPORTANCE: ZIKV is an emerging arbovirus that has been associated with severe neurological birth defects and fetal loss in pregnant women and Guillain-Barré syndrome in adults. Currently, there is no vaccine or therapeutic for ZIKV. The identification of a class of antibodies (envelope dimer epitope 1 [EDE1]) that potently neutralizes ZIKV in addition to all four DENV serotypes points to a potential immunotherapeutic to combat ZIKV. This is especially salient given the precedent of antibody therapy to treat pregnant women infected with other viruses associated with microcephaly, such as cytomegalovirus and rubella virus. Furthermore, the identification of a functionally conserved epitope between ZIKV and DENV raises the possibility that a vaccine may be able to elicit neutralizing antibodies against both viruses.


Assuntos
Anticorpos Monoclonais/administração & dosagem , Anticorpos Neutralizantes/administração & dosagem , Anticorpos Antivirais/administração & dosagem , Reações Cruzadas , Vírus da Dengue/imunologia , Infecção por Zika virus/terapia , Zika virus/imunologia , Animais , Anticorpos Monoclonais/imunologia , Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/imunologia , Modelos Animais de Doenças , Epitopos/imunologia , Humanos , Camundongos , Testes de Neutralização , Resultado do Tratamento
14.
Biochim Biophys Acta ; 1537(1): 58-62, 2001 Jul 27.
Artigo em Inglês | MEDLINE | ID: mdl-11476963

RESUMO

In order to develop transgenic animal models that selectively overexpress various Abeta peptides, we have developed a novel expression system that selectively expresses Abeta40 or Abeta42 in the secretory pathway. This system utilizes fusion constructs in which the sequence encoding the 23-amino-acid ABri peptide at the carboxyl terminus of the 266-amino-acid type 2 transmembrane protein BRI is replaced with a sequence encoding either Abeta40 or Abeta42. Constitutive processing of the resultant BRI-Abeta fusion proteins in transfected cells results in high-level expression and secretion of the encoded Abeta peptide. Significantly, expression of Abeta42 from the BRI-Abeta42 construct resulted in no increase in secreted Abeta40, suggesting that the majority of Abeta42 is not trimmed by carboxypeptidase to Abeta40 in the secretory pathway.


Assuntos
Peptídeos beta-Amiloides/genética , Amiloide/genética , Proteínas Recombinantes de Fusão/genética , Proteínas Adaptadoras de Transdução de Sinal , Animais , Linhagem Celular , Células Cultivadas , Humanos , Glicoproteínas de Membrana , Proteínas de Membrana , Camundongos , Modelos Moleculares , Fragmentos de Peptídeos/biossíntese , Proteínas Recombinantes de Fusão/biossíntese , Transfecção
15.
Trends Mol Med ; 7(10): 467-70, 2001 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-11597522

RESUMO

Intraneuronal filamentous inclusions composed of the microtubule-associated protein tau are a feature of several neurodegenerative diseases (including Alzheimer's disease) known as tauopathies. A pivotal finding was the identification in 1998 of mutations in tau associated with frontotemporal dementia with parkinsonism linked to chromosome 17. This demonstrated that tau dysfunction is sufficient to cause neurodegeneration, and indicated that tau is likely to play a crucial role in the pathogenesis of other tauopathies. However, the mechanism by which tau filamentous lesions form and their role in neurodegeneration remains uncertain. Recent progress in the development of transgenic mouse models of human tauopathy is allowing these questions to be addressed.


Assuntos
Modelos Animais de Doenças , Tauopatias/genética , Tauopatias/metabolismo , Proteínas tau/metabolismo , Animais , Quinase 3 da Glicogênio Sintase , Camundongos , Camundongos Transgênicos , Proteínas Associadas aos Microtúbulos/metabolismo , Neurofibrilas/patologia , Proteínas Serina-Treonina Quinases/genética , Proteínas Serina-Treonina Quinases/metabolismo , Tauopatias/patologia , Transgenes/genética , Regulação para Cima , Proteínas tau/genética
16.
Mol Endocrinol ; 13(10): 1657-71, 1999 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-10517668

RESUMO

The human progesterone receptor (PR) is expressed as two isoforms, PRA and PRB, which differ in the N-terminal region and exhibit different activities in vitro, with PRA demonstrating dominant negative inhibitory effects on the activity of PRB and other nuclear receptors. PRA and PRB are expressed in target tissues at comparable levels although cells expressing a predominance of one isoform can be identified. In breast cancers, PRA is expressed at high levels in some tumors, and this may be associated with features of poorer prognosis. To investigate the role of PRA overexpression in PR-positive target cells, the effect of PRA induction on cell proliferation and expression of endogenous progestin-sensitive genes, SOX4 and fatty acid synthetase (FAS), was examined using PR-positive T-47D cell lines, which express a predominance of PRB, in which PRA could be increased 2- to 20-fold over basal levels. No effect of PRA induction was noted on cell proliferation, but marked changes in morphology, consistent with loss of adherent properties, were observed. Increases up to 4-fold in the relative PRA levels augmented progestin induction of SOX4 mRNA expression, and RU486 treatment revealed a progestin agonist effect. There was no consistent effect of PRA induction on progestin-mediated increases in FAS mRNA levels under these conditions. Clones with PRA:PRB ratios greater than 15 were associated with diminished progestin responses on both SOX4 and FAS mRNA expression. These data show that PRA overexpression is associated with alteration in adhesive properties in breast cancer cells and effects on endogenous progestin targets that were dependent on the cellular ratio of PRA:PRB. The results of this study are consistent with the view that PRA expression can fluctuate within a broad range in target cells without influencing the nature of progestin action on downstream targets, but that overexpression of PRA, such as is seen in a proportion of breast cancers, may be associated with inhibition of progestin action and features of poor prognosis.


Assuntos
Neoplasias da Mama/metabolismo , Progestinas/metabolismo , Receptores de Progesterona/metabolismo , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/genética , Divisão Celular , Ácido Graxo Sintases/genética , Ácido Graxo Sintases/metabolismo , Feminino , Regulação Neoplásica da Expressão Gênica , Proteínas de Grupo de Alta Mobilidade/genética , Proteínas de Grupo de Alta Mobilidade/metabolismo , Humanos , Isopropiltiogalactosídeo/farmacologia , Plasmídeos , Progestinas/farmacologia , Receptores de Progesterona/efeitos dos fármacos , Receptores de Progesterona/genética , Fatores de Transcrição SOXC , Fatores de Tempo , Transativadores/genética , Transativadores/metabolismo , Transcrição Gênica , Transfecção , Células Tumorais Cultivadas
17.
Arch Intern Med ; 140(8): 1101-3, 1980 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-7190377

RESUMO

Two cases of adult-onset idiopathic thrombocytopenic purpura (ITP), refractory to conventional therapy, were treated. Because of recent successful reports of plasma exchange in ITP, this technique was performed on each patient. In both cases, the therapy was unsuccessful in controlling their disease, suggesting that in refractory adult-onset ITP, plasma exchange may not be an effective mode of therapy.


Assuntos
Transfusão Total , Plasma , Púrpura Trombocitopênica/terapia , Adulto , Humanos , Masculino , Pessoa de Meia-Idade , Púrpura Trombocitopênica/diagnóstico , Púrpura Trombocitopênica/tratamento farmacológico
18.
J Clin Endocrinol Metab ; 84(8): 2963-71, 1999 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-10443705

RESUMO

The human progesterone receptor (PR) is expressed as two isoforms, PRA and PRB, that function as ligand-activated transcription factors. In vitro studies suggest that the isoforms differ functionally and that the relative levels in a target cell may determine the nature and magnitude of response to progesterone. However, it is not known whether the two isoforms are normally coexpressed in vivo. To understand the functional significance of relative PR isoform expression in normal physiology, it is essential to determine whether PRA and PRB are coexpressed in the same cell. This study reports the development of a dual immunofluorescent staining technique to demonstrate PRA and PRB proteins by single cell analysis in the same tissue section of human endometrium during the menstrual cycle. PRA and PRB are coexpressed in target cells of the human uterus. In the glands, PRA and PRB were expressed before subnuclear vacuole formation and glycogenolysis, implicating both isoforms in this process, whereas persistence of PRB during the midsecretory phase suggested its significance in glandular secretion. In the stroma, the predominance of PRA throughout the cycle implicates this isoform in post-ovulatory progesterone-mediated events. These results support the view that PRA and PRB mediate distinct pathways of progesterone action in the glandular epithelium and stroma of the human uterus throughout the menstrual cycle.


Assuntos
Endométrio/química , Ciclo Menstrual/metabolismo , Receptores de Progesterona/análise , Núcleo Celular/química , Endométrio/ultraestrutura , Feminino , Imunofluorescência , Humanos , Progesterona/fisiologia , Coloração e Rotulagem
19.
J Mol Endocrinol ; 31(2): 241-53, 2003 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-14519093

RESUMO

Changes in the cell cytoskeleton occur in cell transformation and recent data suggest the involvement of ovarian hormones, which are implicated in cancer development and progression. In human breast and endometrial tumors, there is disrupted expression of progesterone receptor (PR) isoforms and predominance of one isoform, usually PRA. PRA predominance is an early event in carcinogenesis, and in cancers is associated with poor clinical features. Overexpression of PRA in vitro causes altered progestin regulation of cell morphology, suggesting that PRA overexpression may provoke deleterious changes in cell functioning. This study aimed to identify pathways of cytoskeleton regulation responsive to progestins and to determine whether these are perturbed when PRA is overexpressed to the levels seen in cancers. Progestin treatment of PR-positive breast cancer cells caused increased cell surface area whereas after induction of a stably integrated PRA construct, cells became rounded and the cell surface was decreased. The effect of PRA induction on cell rounding was reversed by the anti-progestin RU38486. Altered tropomyosin (Tm) isoforms were implicated in these morphological differences, as there was a PRA-mediated alteration in Tm5 isoform levels, and transfection of Tm5a mimicked progestin-mediated cell rounding in PRA-overexpressing cells. Ezrin was redistributed from the membrane to cytoplasmic locations in the presence of progestin, and discrete focal localization was evident in cells with PRA predominance. Progestin effects on the cytoskeleton in PRA-overexpressing cells provide evidence for novel endocrine regulation of aspects of actin microfilament composition, suggesting that changes in the cytoskeleton known to be associated with cancer development and progression may be regulated in part by altered PRA expression which develops early in carcinogenesis.


Assuntos
Citoesqueleto de Actina/metabolismo , Progestinas/metabolismo , Receptores de Progesterona/metabolismo , Transdução de Sinais/fisiologia , Actinas/metabolismo , Animais , Proteínas do Citoesqueleto/metabolismo , Feminino , Adesões Focais/metabolismo , Neoplasias Mamárias Animais/metabolismo , Neoplasias Mamárias Animais/patologia , Fosfoproteínas/metabolismo , Progestinas/farmacologia , Ratos , Transdução de Sinais/efeitos dos fármacos , Transativadores/metabolismo , beta Catenina
20.
J Med Chem ; 35(11): 2048-54, 1992 May 29.
Artigo em Inglês | MEDLINE | ID: mdl-1597856

RESUMO

Ester and amide derivatives of E64c, (+)-(2S,3S)-3-[[(S)-3-methyl-1- [(3-methylbutyl)carbamoyl]butyl]carbamoyl]-2-oxiranecarboxylic acid, an inhibitor of calpains, were synthesized and tested for ability to inhibit calpain in lysed cells, ability to enter intact cells, and ability to inhibit calpain in intact cells. The esters were from halogen-substituted alcohols and alcohols with increasing size. There were no appreciable differences in the inhibitory potency of any of the halogen-substituted esters from ethyl to trifluoroethyl, indicating that ease of hydrolysis of this class of ester is not important for activity. The only ester with impaired activity was the largest, Z-leucyl-norleucyl, which was about 5% as effective as the ethyl ester, E64d. Amides of amino acid esters also had impaired activity. To explore the possibility of targeting E64c derivatives to specific cells, esters and amides of E64c with 5-hydroxytryptamine were tested on the rationale that the active 5-hydroxytryptamine uptake mechanism of platelets might selectively concentrate the drug in platelets. Both the ester and amide inhibited calpain in lysed cells, but only the ester inhibited in intact cells. The 5-hydroxytryptamine ester showed no advantage over the ethyl ester in entering platelets.


Assuntos
Plaquetas/enzimologia , Calpaína/antagonistas & inibidores , Inibidores de Cisteína Proteinase/síntese química , Leucina/análogos & derivados , Adulto , Plaquetas/efeitos dos fármacos , Plaquetas/metabolismo , Calcimicina/farmacologia , Cálcio/farmacologia , Inibidores de Cisteína Proteinase/farmacologia , Ésteres/farmacologia , Humanos , Leucina/química , Leucina/farmacologia , Serotonina/sangue , Relação Estrutura-Atividade
SELEÇÃO DE REFERÊNCIAS
Detalhe da pesquisa